The structure of a membrane adenylyl cyclase bound to an activated stimulatory G protein.Qi, C., Sorrentino, S., Medalia, O., Korkhov, V.M.
(2019) Science 364: 389-394
- PubMed: 31023924
- DOI: https://doi.org/10.1126/science.aav0778
- Primary Citation of Related Structures:
6R3Q, 6R4O, 6R4P
- PubMed Abstract:
Membrane-integral adenylyl cyclases (ACs) are key enzymes in mammalian heterotrimeric GTP-binding protein (G protein)-dependent signal transduction, which is important in many cellular processes. Signals received by the G protein-coupled receptors are conveyed to ACs through G proteins to modulate the levels of cellular cyclic adenosine monophosphate (cAMP). Here, we describe the cryo-electron microscopy structure of the bovine membrane AC9 bound to an activated G protein αs subunit at 3.4-angstrom resolution. The structure reveals the organization of the membrane domain and helical domain that spans between the membrane and catalytic domains of AC9. The carboxyl-terminal extension of the catalytic domain occludes both the catalytic and the allosteric sites of AC9, inducing a conformation distinct from the substrate- and activator-bound state, suggesting a regulatory role in cAMP production.
Institute of Biochemistry, ETH Zurich, Zurich, Switzerland.